Various techniques have been proposed to provide broadcast services within a cellular network. For example, Multimedia Broadcast Multicast Service (MBMS) is a broadcast service that has been proposed for implementation within Global System for Mobile Communications (GSM) and Universal Mobile Telecommunications System (UMTS) cellular networks. MBMS is split into a bearer service and a user service. The bearer service includes a multicast mode and a broadcast mode, and the user service offers a streaming delivery method and a download delivery method. The streaming delivery method can be used for a continuous transmission, such as mobile television (TV) services, and the download method is intended for download-and-play services.
Recently, the Institute of Electrical and Electronics Engineers (IEEE) promulgated a standard (i.e., IEEE 802.16) for local and metropolitan area networks. More specifically, IEEE 802.16e describes requirements for an air interface for fixed and mobile broadband wireless access systems. The Worldwide Interoperability for Microwave Access (WiMAX) forum was formed to promote conformance and interoperability of the IEEE 802.16 standard. In general, technology that conforms to the IEEE 802.16 standard facilitates delivery of last mile wireless broadband access, as an alternative to cable and digital subscriber line (DSL) services. IEEE 802.16 defines a multicast and broadcasting service (MBS) that is implemented in a single frequency network (SFN) configuration, as opposed to a multi-frequency network configuration. As is known, a typical cellular network has employed a number of different channels (frequency bands) to reduce interference between neighboring cells of the cellular network and has reused frequency bands in non-adjacent cells.
IEEE 802.16e, which is based on orthogonal frequency division multiple access (OFDMA), defines a partial use of subcarrier (PUSC) operation mode in which a channel is divided into orthogonal segments each with non-overlapping subcarrier permutations and a full use of subcarrier (FUSC) operation mode in which all subcarriers of a channel overlap. IEEE 802.16e defines a zone of a frame to include a number of contiguous OFDMA symbols in an uplink (UL) or downlink (DL) that use the same operation mode. A DL or UL sub-frame may include one or more zones and may switch between the PUSC and FUSC operation modes between zones. In the PUSC operation mode, neighboring base stations (BSs) may be assigned to different segments to reduce interference between the neighboring BSs. In the FUSC operation mode, all BSs are assigned to use the entire channel.
In order to decode a certain MBS content in IEEE 802.16e MBS service, a mobile station (MS) first decodes DL-MAP that includes DL-MAP-IE( ) or MBS-MAP-IE( ). Either of these Information Element (IE) points are mapped to an MBS-MAP in the MBS time zone within a radio frame. The MBS-MAP includes MBS-DATA-IE( ) that tells the specific location for a MBS content that is of interest to the SS. Thereafter, the SS operates in one of two processes. The SS either locates the next MBS-MAP from the present MBS-MAP directly (i.e., DL-MAP→MBS-MAP→Data→MBS-MAP→Data and so on); or, the SS repeats the original procedure for locating each MBS-MAP (i.e., DL-MAP→MBS-MAP→Data→DL-MAP and so forth).